Monday, 23 January 2012

MZ 500 Silverstar

In the not too distant past I did a Grand Tour of Europe on a 15 year old MZ 250. It took over six months, both a comment on its lack of speed and my laid back attitude. The MZ expired in France from a locked up gearbox that led to a slide down the road. The clock read over 100,000 miles and by the time I picked myself up, the whole bike was just about wrecked. I dumped it the nearest ditch......it had only cost twenty quid and ran tirelessly.

After a couple of years work I had a nice bundle of loose cash with which to buy something newer. I've always liked big singles so when a MZ Silver Star turned up in the local paper for £3200 I went for a look. The bike was absolutely immaculate, 6500 miles on the clock. A 1993 model, it seemed to lack the functional lines of the old strokers but the Rotax engine had a reputation for taking massive abuse. I offered £2500, ended up paying £2625.

That's a lot of dosh even for a nearly new bike. I could buy ten MZ 250s for that or a four year old race replica 600. But what I wanted was the practicality and functionality of the old 250, together with the reassurance of a four stroke design. And that, it's turned out, is pretty much what I got.

The centre-piece of the bike is the four valve thumper motor. It makes only 34 horses but churns out a most respectable 42ftlb of torque, with a bore and stroke of 89x79mm. These features add up to characteristics that are a long way from the charming (when they're running) old singles of the fifties. Below 2500rpm there was hardly any power, making the MZ awkward to ride in the taller of the five gears. A gentle throttle hand maintained forward motion and allowed marginal acceleration, until 2500 revs were reached when power flowed well.

The red line's at 7500rpm but few long term owners will want to venture much beyond 6500 revs. Not that the motor's going to explode, just that the primary vibes start churning away. All things are relative, the Rotax engine's level of vibes at max revs is about the same as an old Bonnie at tickover. Anyone coming from a British bike will find it smooth, but those forsaking the Japanese Way will take a while to adapt. However, my back fillings never came close to tingling, let alone falling out.

Part of this is from the continuing MZ tradition of producing narrow, light motorcycles. Even though the chassis has a more conventional look than the stroker there isn't all that much metal to absorb the vibration. Better this than lumbering a bike with excessive weight that kills consumables, ruins handling and wrecks economy.

In many ways the Silver Star continues the traditions of the stroker range in getting more out of less. The suspension is utterly conventional stuff, reasonably taut and quite willing to absorb bumps. With less than 350lbs to react against the suspension has a relatively easy time. With the motor mounted quite low, the whole machine splendidly compact, there is a natural, neutral feel reminiscent of the 250 but somehow even better.

Even on the low tech rubber I found I could ear-hole the bike without much thought or effort and without any fear and loathing. It felt so light that midway through bends I had no reluctance in pulling the bike upright, slamming on the anchors and changing direction when some obstacle occurred.

There was a slight weave when it was thrashed up to 95mph but the buzzing wouldn't let me hold it for too long so it never got out of shape. 70 to 75mph was a much more realistic speed, though at a pinch 80mph could be maintained for an hour or so. The ultimate lack of top speed and excessive acceleration meant that high speed passing manoeuvres required an undue amount of thought and planning. Several times I was thankful for the overall narrowness, it allowed me to pass between two converging cars with mere inches to spare when the engine ran out of puff to complete the overtaking manoeuvre.

This would've been serious had I been a fast A-road or motorway addict but I was much more interested in using the MZ on curving back lanes, where the handling and power were nigh on perfect. It was relaxing to ride when I wanted to relax and fun when I wanted to hustle a little.

The brakes were a combination of single front disc and rear drum. These were definitely new world items, having nothing in common with the dangerous old drums fitted to previous MZs. As much as I grew to love my MZ 250 on that European tour, many a time I cursed the abysmal front drum that would fade away to absolutely nothing. The disc was well matched to the chassis and power, nailing down the front end progressively without going into cartwheel mode unless wrist snapping effort was put out. A useful degree of sensitivity enabled safe braking in the wet, backed up by the rear drum and reasonable engine braking.

The gearbox and clutch worked well, though down-changes took a little getting used to as the transmission would lurch and clatter unless care was taken to match engine revs and road speed. Part of that was down to a chain that seemed made out of mild steel. Despite the full chain enclosure, and the odd bit of lubrication, adjustments were frequent and less than a 1000 miles of additional abuse had it trying to whip through the enclosure. A new chain was much better, though, shoring up the gearchange and not needing much by way of attention.

Oil consumption (it's contained in the upper box section frame member) was minimal and fuel proved to be much better than on the old strokers. One of the most curious things about modern multi's is that they don't have good economy at low revs. This is strange because internal frictional losses are small at low revs, much more significant at the top of the rev range. It would be interesting to see how a four cylinder engine designed for low revs and torque (as in the automobile world) fared on economy.

The MZ, by contrast, varied its consumption between 55 and 80mpg, dependent almost entirely on how the revs were used. Thrashed flat out brought in the former figure whilst the latter was achieved on 40mph country rambles. General riding gave 60 to 70mpg, the latter figure available without too much thought. The tank held less than three gallons, meaning range was still better than 150 miles.

Comfort was pretty good. The riding position was natural enough for me, though those who are taller than my 5'9'' might find themselves a little cramped. Mild backside pains set in after about 90 miles and by the time it was ready for a fuel up I was only too happy to stretch my legs. I did find that my endurance improved over the months I've owned the bike and I'm now able to survive 400 or so miles in day without staggering around in agony.

Controls and lights were just about adequate rather than brilliant. Finish has proved good except for a spot of rust on the rear shocks and the exhaust, both of which polished up. On colder days the electric starter rumbled away but I never actually had to resort to the kickstart, which was just as well as it was mounted on the left side and I'd had enough trouble mastering the gentle kick needed to start the old MZ 250.

Once the engine was warmed up - maybe five minutes in winter - I could roar around town without any troubles, the MZ feeling more like a 250, or even a 125, than a full bloodied 500 thumper in the way it could be weaved through doubtful gaps. The only slight worry was the need to rev the engine at junctions to stop it cutting out, a tendency emphasized when the clutch was pulled in, due to slight drag after an hour or so in traffic. Raising the tickover to 1500rpm helped but left the engine sounding rather frantic when idling in neutral.

On the upside, with 11000 miles on the clock, all the engine's had is a couple of oil changes and one valve check (all four were within limits). The motor's been around for a long time, used in military bikes as well as the Matchless G80, proved itself tough and long lasting.

The Rotax engine is used to power five different models, the others having a more functional, Teutonic appearance but being very rare. However, the Silver Star's appearance has grown on me over the months and I'm quite happy with it. Now that we are old friends, have tested each others limits, I'm all set to hit the Continent, and beyond, for a year's touring. I reckon the money I'll save on fuel and consumables over, say 25000 miles, will more than repay the cost of the machine compared with a Japanese equivalent.

Howard Evans